Multi-harmonic absorption multiplexing and active device limit use method of network-forming converter

Abstract

The invention discloses a multi-harmonic absorption multiplexing and active device limit use method of a network-forming converter. Comprising the following steps: determining a corresponding objective function according to a pre-established active device loss model under a multi-harmonic absorption multiplexing control architecture of the network-forming converter; the objective function at least comprises an active device limit use objective function and a harmonic weight objective function; based on the active power and the reactive power obtained through real-time measurement, a preset multi-objective optimization algorithm is used for carrying out iterative solution on an active device limit use objective function and a harmonic weight objective function, and a target harmonic absorption current instruction is obtained; and based on the target harmonic absorption current instruction, carrying out harmonic absorption multiplexing control on the network-forming converter. The time-varying characteristic of the active working condition of the grid-forming converter is fully utilized, and the extra capacity is reused to absorb power grid harmonics, so that the limit use of active devices is realized, the utilization rate of the grid-forming converter is improved, the harmonic level of the power grid is reduced, and the power quality of the power grid is improved.

Description

Technical Field

[0001] The present invention relates to the field of grid connection technology, and in particular to a method for absorbing and multiplexing multiple harmonics of a grid-connected converter and limiting the use of its active components. Background Art

[0002] In the new power system, the grid-connected converter can connect various distributed renewable energy sources and energy storage systems to the grid in a distributed manner. At the same time, the active power output condition of the grid-connected converter itself changes over time. In most operating times, it does not reach the rated value or the maximum value, resulting in a waste of converter capacity. Therefore, effectively reusing the extra capacity of this part of the converter for grid harmonic absorption has high research and practical value.

[0003] However, the remaining capacity of the converter is not a simple algebraic addition or subtraction of kW or kVA as currently understood by the industry. To understand how much capacity is consumed by the harmonics of the grid-type converter, it is necessary to add the losses of the active devices caused by multiple harmonics and fundamental power to evaluate whether the maximum allowable losses and heat generation have been reached. Under the mixture of multiple harmonic currents, the total loss of the active devices of the grid-type converter is not the sum of the losses calculated for each harmonic separately, and there is a complex coupling relationship between the loss models of each harmonic, resulting in the active devices not being fully utilized. Therefore, how to effectively reuse the remaining capacity of the converter for harmonic absorption on a grid-type control architecture while achieving the maximum use of active devices is a problem that needs to be solved. Summary of the invention

[0004] The present invention provides a method for multiplexing multi-harmonic absorption of a meshed converter and limiting the use of its active devices, so as to solve the problem that the remaining capacity of the converter cannot be effectively multiplexed for harmonic absorption in a meshed control architecture and the active devices cannot be used to the fullest extent.

[0005] According to one aspect of the present invention, a method for absorbing and multiplexing multiple harmonics of a grid-type converter and limiting the use of its active components is provided, the method comprising:

[0006] According to the pre-established active device loss model under the multi-harmonic absorption multiplexing control architecture of the grid-type converter, the corresponding objective function is determined; wherein the objective function at least includes: an active device limit utilization objective function and a harmonic weight objective function; the multi-harmonic absorption multiplexing control architecture of the grid-type converter includes: a basic grid-type control architecture, a current harmonic component calculation module and a harmonic compensation calculation module;

[0007] Based on the real-time measured active power and reactive power, the preset multi-objective optimization algorithm is used to iteratively solve the active device limit utilization objective function and the harmonic weight objective function to obtain the target harmonic absorption current instruction;

[0008] Harmonic absorption multiplexing control is performed on the grid-connected converter based on the target harmonic absorption current instruction.

[0009] According to another aspect of the present invention, a device for absorbing and multiplexing multiple harmonics of a grid-type converter and limiting the use of active components thereof is provided, the device comprising:

[0010] The objective function determination module is used to determine the corresponding objective function according to the pre-established active device loss model under the multi-harmonic absorption multiplexing control architecture of the grid-type converter; wherein the objective function at least includes: the active device limit utilization objective function and the harmonic weight objective function; the multi-harmonic absorption multiplexing control architecture of the grid-type converter includes: the basic grid-type control architecture, the current harmonic component calculation module and the harmonic compensation calculation module;

[0011] The instruction solving module is used to iteratively solve the active device limit utilization objective function and the harmonic weight objective function based on the real-time measured active power and reactive power using a preset multi-objective optimization algorithm to obtain the target harmonic absorption current instruction;

[0012] The harmonic absorption multiplexing control module is used to perform harmonic absorption multiplexing control on the grid-type converter based on the target harmonic absorption current instruction.

[0013] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0014] at least one processor; and

[0015] a memory communicatively connected to the at least one processor; wherein,

[0016] The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the multi-harmonic absorption multiplexing of the grid-type converter and the method for limiting the use of its active devices as described in any embodiment of the present invention.

[0017] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the multi-harmonic absorption multiplexing of a grid-type converter and the method for limiting the use of its active devices as described in any embodiment of the present invention when executed.

[0018] The technical solution of the embodiment of the present invention determines the corresponding active device maximum utilization objective function and harmonic weight objective function according to the active device loss model constructed under the multi-harmonic absorption multiplexing control architecture of the grid-type converter, and then uses the active power and reactive power obtained by real-time measurement under the current working conditions as the input of the preset multi-objective optimization algorithm, and iteratively solves the active device maximum utilization objective function and the harmonic weight objective function to obtain the optimal target harmonic absorption current instruction, and then performs harmonic absorption multiplexing control on the grid-type converter based on the target harmonic absorption current instruction, which solves the problem that the remaining capacity of the converter cannot be effectively reused for harmonic absorption in the grid-type control architecture, and the active devices cannot be fully utilized, and makes full use of the time-varying active working conditions of the grid-type converter, reuses its extra capacity to absorb grid harmonics, so as to achieve the maximum utilization of its active devices, improves the utilization rate of the grid-type converter, and reduces the grid harmonic level, thereby improving the power quality of the grid.

[0019] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 2 is a schematic diagram of a multi-harmonic absorption multiplexing control architecture of a grid-type converter provided according to Embodiment 1 of the present invention;

[0022] Figure 2 This is a flow chart of a method for multi-harmonic absorption and multiplexing of a grid-type converter and limited use of its active components provided according to the first embodiment of the present invention;

[0023] Figure 3 This is a flow chart of a method for multi-harmonic absorption and multiplexing of a grid-type converter and limited use of its active components according to the second embodiment of the present invention;

[0024] Figure 4 This is a flow chart of another method for multi-harmonic absorption and multiplexing of a grid-type converter and limited use of its active components provided according to the second embodiment of the present invention;

[0025] Figure 5 is a fitness evolution curve provided according to the second embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the structure of a multi-harmonic absorption multiplexing device of a grid-type converter and a device for limiting the use of its active components according to Embodiment 3 of the present invention;

[0027] Figure 7 It is a structural schematic diagram of an electronic device for realizing the multi-harmonic absorption multiplexing of a grid-type converter and the method for limiting the use of its active components according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] Embodiment 1

[0031] Figure 1 This is a schematic diagram of a multi-harmonic absorption multiplexing control architecture for a grid-type converter provided in the first embodiment of the present invention. Figure 1 As shown, the multi-harmonic absorption multiplexing control architecture of the grid-type converter of this embodiment includes the following two parts:

[0032] (1) Basic network control architecture:

[0033] Based on the basic grid-type control architecture, the voltage u of the filter capacitor connected to the grid can be sampled. c and grid-side current i 2 , input to the instantaneous power calculation module to determine the instantaneous active power P output by the converter out and instantaneous reactive power Q out ; Then the instantaneous active power P out and instantaneous reactive power Qout And the given preset active power P set and preset reactive power Q set Input to the power loop, generate a reference voltage amplitude V by simulating the rotor motion and excitation characteristics of the synchronous generator ref and virtual angular frequency ω m , and then by the virtual angular frequency ω m The reference voltage phase θ is obtained by integration ref ; Then the reference voltage amplitude V ref and the reference voltage phase θ ref Input to the voltage command calculation module to obtain the reference voltage command u ref ; Set the reference voltage instruction u ref It is transmitted to the instruction side before the voltage and current dual closed-loop control module as the fundamental reference voltage to achieve basic networking control. Figure 1 In, G u is the transfer function of the voltage outer loop controller, G i is the transfer function of the current inner loop controller.

[0034] (2) Multi-harmonic absorption multiplexing control architecture:

[0035] By taking the sampled grid-side current i 2 The current harmonic component calculation module is sent to calculate the grid-side current harmonic component i gh , and then compare it with the input harmonic absorption current command i ref.h After the difference is made, the harmonic voltage command u is generated in a closed loop through the harmonic compensation calculation module. ref.h ; Then the harmonic voltage command u ref.h With the aforementioned reference voltage command u ref After superposition, voltage and current dual closed-loop control and pulse width modulation (PWM) are performed, and the multi-harmonic absorption multiplexing control architecture of the grid-type converter is controlled to realize the multi-harmonic absorption multiplexing of the grid-type converter.

[0036] Based on the above-mentioned grid-type converter multi-harmonic absorption multiplexing control architecture, Figure 2 A flowchart of a method for multiple harmonic absorption and multiplexing of a meshed converter and the limited use of its active devices is provided for the first embodiment of the present invention. This embodiment is applicable to the situation where a meshed converter is used for harmonic absorption and multiplexing to achieve the limited use of its active devices. The method can be performed by a device for multiple harmonic absorption and multiplexing of a meshed converter and the limited use of its active devices. The device for multiple harmonic absorption and multiplexing of a meshed converter and the limited use of its active devices can be implemented in the form of hardware and / or software. The device for multiple harmonic absorption and multiplexing of a meshed converter and the limited use of its active devices can be configured in an electronic device. Figure 2As shown, the first embodiment provides a method for absorbing and multiplexing multiple harmonics of a grid-type converter and limiting the use of its active components, which specifically includes the following steps:

[0037] S110. Determine the corresponding objective function according to the pre-established active device loss model under the multi-harmonic absorption multiplexing control architecture of the grid-type converter; wherein the objective function at least includes: an active device maximum utilization objective function and a harmonic weight objective function; the multi-harmonic absorption multiplexing control architecture of the grid-type converter includes: a basic grid-type control architecture, a current harmonic component calculation module, and a harmonic compensation calculation module.

[0038] The active devices may include at least electronic components such as insulated gate bipolar transistors (IGBT) and diodes in the grid-type converter. The active device loss model may include at least a conduction loss model and a switching loss model of the active device.

[0039] The objective function may refer to a dual optimization objective for characterizing that the loss of active devices of a grid-type converter reaches an upper limit and complies with the weight ratio distribution of each harmonic. The objective function may at least include: an active device limit utilization objective function and a harmonic weight objective function. Among them, the active device limit utilization objective function can be used to characterize the loss of active devices of a grid-type converter; the harmonic weight objective function can be used to characterize the weight ratio distribution of each harmonic.

[0040] In the embodiment of the present invention, it can be based on Figure 1 The multi-harmonic absorption and multiplexing control architecture of the constructed grid-type converter, as well as the active devices such as IGBTs and diodes contained in the grid-type converter, are used to establish corresponding active device loss models, such as the conduction loss model and the switching loss model of the active devices. At the same time, an objective function is established with the active device loss reaching an upper limit and meeting the weight ratio distribution of each harmonic as the optimization goal. The objective function includes at least: an active device limit utilization objective function and a harmonic weight objective function.

[0041] S120, based on the real-time measured active power and reactive power, use a preset multi-objective optimization algorithm to iteratively solve the active device limit utilization objective function and the harmonic weight objective function to obtain a target harmonic absorption current instruction.

[0042] Among them, the preset multi-objective optimization algorithm may refer to a pre-configured method for solving optimization problems of multiple objective functions. Exemplarily, the preset multi-objective optimization algorithm may include but is not limited to: particle swarm optimization algorithm, genetic algorithm, differential evolution algorithm and simulated annealing algorithm, etc.

[0043] The target harmonic absorption current instruction may refer to the optimal harmonic absorption current instruction (i.e. Figure 1 i ref.h ), that is, the target harmonic absorption current instruction at this time can meet the dual optimization goals of the active device loss of the grid-type converter reaching the upper limit (active limit) and meeting the weight proportion distribution of each harmonic (multi-harmonic absorption). The harmonic absorption current instruction can include the following information: the amplitude of each harmonic absorption current and the phase of each harmonic absorption current.

[0044] In the embodiment of the present invention, the active power P output by the converter under the multi-harmonic absorption multiplexing control architecture of the grid-type converter can be collected by the grid data collection device. out and reactive power Q out , and then the active power P out and reactive power Q out As the input of the preset multi-objective optimization algorithm, the active device limit use objective function and the harmonic weight objective function are iteratively solved to obtain the target harmonic absorption current instruction that can meet the dual optimization goals of the active device loss of the grid-type converter reaching the upper limit (active limit) and meeting the weight ratio distribution of each harmonic (multi-harmonic absorption). In a specific embodiment, specifically, taking the particle swarm optimization algorithm as an example, the active device limit use objective function and the harmonic weight objective function can be used as the fitness function of the particle swarm optimization algorithm, and the harmonic absorption current instruction to be optimized is used as a particle in the particle swarm, and then the active power and reactive power obtained by real-time measurement and the optimization constraints corresponding to the particle swarm optimization algorithm are used to continuously iterate each particle in the particle swarm, and after the iteration termination condition is met, the final target harmonic absorption current instruction is determined according to the group extreme value (global optimal solution) corresponding to the current particle swarm.

[0045] S130. Perform harmonic absorption multiplexing control on the grid-connected converter based on the target harmonic absorption current instruction.

[0046] In the embodiment of the present invention, it can be based on Figure 1 The grid-type converter multi-harmonic absorption multiplexing control architecture shown in the figure determines the target harmonic absorption current instruction i ref.h The harmonic component i of the grid-side current gh After the difference is made, the harmonic voltage command u is generated in a closed loop through the harmonic compensation calculation module. ref.h ; Then use the harmonic voltage command u ref.h With reference voltage command u refThe voltage and current dual closed-loop control and PWM modulation are performed to control the grid-type converter to achieve multiple harmonic absorption reuse. Based on the target harmonic absorption current instruction, it can be reused to absorb multiple harmonics of the power grid under the condition of active and reactive power changes of the grid-type converter to achieve the maximum use of its active devices, thereby improving the utilization rate of the grid-type converter and helping to reduce the harmonic level of the power grid.

[0047] The technical solution of the embodiment of the present invention determines the corresponding active device maximum utilization objective function and harmonic weight objective function according to the active device loss model constructed under the multi-harmonic absorption multiplexing control architecture of the grid-type converter, and then uses the active power and reactive power obtained by real-time measurement under the current working conditions as the input of the preset multi-objective optimization algorithm, and iteratively solves the active device maximum utilization objective function and the harmonic weight objective function to obtain the optimal target harmonic absorption current instruction, and then performs harmonic absorption multiplexing control on the grid-type converter based on the target harmonic absorption current instruction, which solves the problem that the remaining capacity of the converter cannot be effectively reused for harmonic absorption in the grid-type control architecture, and the active devices cannot be fully utilized, and makes full use of the time-varying active working conditions of the grid-type converter, reuses its extra capacity to absorb grid harmonics, so as to achieve the maximum utilization of its active devices, improves the utilization rate of the grid-type converter, and reduces the grid harmonic level, thereby improving the power quality of the grid.

[0048] Embodiment 2

[0049] Figure 3 The flowchart of a method for multiple harmonic absorption and multiplexing of a grid-type converter and its active device limiting use provided in the second embodiment of the present invention is further optimized and expanded based on the above implementation, and can be combined with various optional technical solutions in the above implementation. Figure 3 As shown, the second embodiment provides a method for multiple harmonic absorption and multiplexing of a grid-type converter and limited use of its active components, which specifically includes the following steps:

[0050] S210, obtaining a pre-established active device loss model under a multi-harmonic absorption multiplexing control architecture of a grid-type converter, and obtaining a pre-configured harmonic weight objective function; wherein the active device loss model includes at least: an IGBT loss model and a diode loss model.

[0051] In the embodiment of the present invention, the data can be obtained from a data storage location such as a local or cloud server. Figure 1The active device loss model and harmonic weight objective function are pre-constructed under the multi-harmonic absorption multiplexing control architecture of the Zhonggou grid-type converter, wherein the active device loss model includes: IGBT loss model and diode loss model, and the IGBT loss model can be constructed based on the conduction loss and switching loss of the converter IGBT, and the diode loss model can be constructed based on the conduction loss and switching loss of the converter diode.

[0052] Further, based on the above-mentioned embodiments of the invention, the active device loss model can be expressed as:

[0053]

[0054] Where P IGBT is the IGBT loss (model); P condIGBT is the IGBT conduction loss; P sw is the IGBT switching loss; P Diode is the diode loss (model); P condDiode is the diode conduction loss; P rec is the diode switching loss.

[0055] Furthermore, the conduction loss model of active devices, that is, the IGBT conduction loss P condIGBT and diode conduction loss P condDiode They can be expressed as follows:

[0056]

[0057] Where f(i,j) is a function of the harmonic order; k is the harmonic order; v CE is the collector-emitter voltage; r CE is the on-resistance of the IGBT in the amplified state; i ac is the AC harmonic combination; V CE0 is the on-state voltage drop; f 1 is the fundamental frequency; is the phase angle of the kth harmonic absorption current; I k is the kth harmonic absorption current amplitude; T 0 is the current cycle; is the power factor angle; ω is the fundamental angular frequency; m is the modulation ratio; I 1 is the fundamental current amplitude; is the fundamental current phase angle; I i is the i-th harmonic absorption current amplitude; I j is the jth harmonic current amplitude; f sw is the IGBT switching frequency; v F is the diode conduction voltage; R on is the on-resistance of the diode.

[0058] Furthermore, the switching loss model of active devices, i.e., the IGBT switching loss P sw and diode switching loss P rec They can be expressed as follows:

[0059]

[0060] Where V DC is the DC voltage; V nom is the DC voltage reference value; a, b, c, a′, b′ and c′ are all coefficients.

[0061] Further, based on the above-mentioned embodiments of the invention, the harmonic weight objective function can be expressed as follows:

[0062]

[0063] Where Q represents the harmonic weight objective function; k represents the harmonic order; h k Indicates the kth harmonic importance weight coefficient; I k Indicates the kth harmonic absorption current amplitude.

[0064] Furthermore, the kth harmonic importance weight coefficient h k It can be expressed as:

[0065]

[0066] In the formula, α j is the sensitivity factor of the jth harmonic.

[0067] S220 , based on the IGBT loss model, the diode loss model and the corresponding rated losses, determine the corresponding IGBT loss limit utilization objective function and the diode loss limit utilization objective function as the active device limit utilization objective function.

[0068] In an embodiment of the present invention, the corresponding active device limit usage objective function can be determined based on the IGBT loss model and diode loss model obtained above, and the rated losses corresponding to the two respectively, wherein the active device limit usage objective function may include: IGBT loss limit usage objective function and diode loss limit usage objective function.

[0069] Further, based on the above-mentioned embodiments of the invention, the objective function of limiting the use of active devices can be expressed as follows:

[0070]

[0071] Among them, δ 1 represents the IGBT wear-out limit usage objective function; P IGBTIndicates IGBT loss; P IGBTN Indicates the rated loss of IGBT; δ 2 represents the diode wear-out limit usage objective function; P Diode Represents diode loss; P DiodeN Indicates the rated loss of the diode.

[0072] S230, obtaining the active power and reactive power measured in real time under the multi-harmonic absorption multiplexing control architecture of the grid-type converter, and calling the preset fundamental current calculation formula according to the active power and reactive power to determine the corresponding fundamental current real-time value.

[0073] In the embodiment of the present invention, the active power P of the current working condition under the multi-harmonic absorption multiplexing control architecture of the grid-type converter can be collected by the grid data collection device. out and reactive power Q out , and then determine the active power P by calling the following preset fundamental current calculation formula out and reactive power Q out The corresponding fundamental current real-time value I:

[0074]

[0075] Where U is the three-phase line voltage.

[0076] S240, obtaining optimization constraints and iteration termination conditions corresponding to the particle swarm optimization algorithm.

[0077] The optimization constraint condition may refer to a condition for limiting the solution space corresponding to the objective function (i.e., the harmonic absorption current instruction). The optimization constraint condition in this embodiment may be: the active device loss value cannot exceed its rated loss, i.e., the IGBT loss P IGBT Cannot exceed the corresponding IGBT rated loss P IGBTN , and the diode loss P Diode Cannot exceed the corresponding diode rated loss P DiodeN .

[0078] The iteration termination condition may refer to the execution termination condition of the preset particle swarm optimization algorithm, and the iteration termination condition may include: the number of iterations reaches the preset maximum number of iterations, the fitness value deviation between two iterative calculations reaches the preset stop tolerance (that is, the difference between the fitness value of the optimal solution after the previous iteration and the fitness value of the optimal solution after this iteration is less than the preset value), etc.

[0079] In an embodiment of the present invention, the optimization constraint conditions and iteration termination conditions corresponding to the particle swarm optimization algorithm to be called subsequently may be obtained from a data storage location such as a local or cloud server.

[0080] Further, based on the above-mentioned embodiments of the invention, the optimization constraint condition can be expressed as follows:

[0081]

[0082] S250: taking the harmonic absorption current instruction to be solved as a particle in the particle swarm, and initializing the position and speed corresponding to each particle based on the optimization constraint condition.

[0083] In an embodiment of the present invention, a pre-configured particle swarm optimization algorithm can be called, and the harmonic absorption current instruction is used as a particle in the particle swarm, and an initialization operation is performed based on the optimization constraint condition, that is, the initialization setting: population size (number of particles), particle dimension (space dimension of particle search, that is, the dimension of the parameter to be optimized), the position of each particle (a solution to the optimization problem to be solved, that is, a certain harmonic absorption current instruction), speed and individual extreme value (individual optimal solution), preset maximum number of iterations, group extreme value (global optimal solution). Among them, the i-th particle in the particle swarm can be expressed as follows:

[0084]

[0085] In the formula, I i is the i-th harmonic absorption current amplitude; is the i-th harmonic absorption current phase.

[0086] S260: Determine the adaptation value corresponding to each particle based on the active device limited utilization objective function, the harmonic weight objective function and the fundamental current real-time value.

[0087] In an embodiment of the present invention, the active device maximum utilization objective function and the harmonic weight objective function can be used as the fitness function of the preset particle swarm optimization algorithm, and then the real-time value of the fundamental current and the amplitude and phase of each harmonic absorption current corresponding to each particle under the current iteration number are substituted into the above fitness function to obtain the fitness value corresponding to each particle in this iteration.

[0088] S270, using the fitness value to update the individual extreme value of the corresponding particle and the group extreme value of the particle group.

[0089] The individual extreme value may refer to the individual optimal solution corresponding to the particle in this iteration, and the group extreme value may refer to the global optimal solution corresponding to the particle group.

[0090] In the embodiment of the present invention, S270 may specifically include:

[0091] If the fitness value of a particle is greater than the fitness value corresponding to the individual extreme value of the particle, the individual extreme value of the particle is updated using the position of the particle in this iteration;

[0092] If the fitness value of a particle is less than the fitness value corresponding to the individual extreme value of the particle, the individual extreme value of the particle is kept unchanged in this iteration;

[0093] If the fitness value of a particle is greater than the fitness value corresponding to the group extreme value of the particle swarm, the group extreme value of the particle swarm is updated using the position of the particle in this iteration;

[0094] If the fitness value of a particle is less than the fitness value corresponding to the group extreme value of the particle swarm, the group extreme value of the particle swarm is kept unchanged in this iteration.

[0095] It should be understood that the position and velocity of the particles in the preset particle swarm optimization algorithm (multi-objective particle swarm optimization algorithm) of this embodiment are still updated according to the method of the single-objective particle swarm optimization algorithm. The difference from the single-objective particle swarm optimization algorithm is that the final result of the single-objective particle swarm optimization algorithm is only one solution, while the final result of the multi-objective particle swarm optimization algorithm is a Pareto optimal solution set composed of a series of Pareto optimal solutions.

[0096] In the preset particle swarm optimization algorithm of this embodiment, the update strategy of the individual extreme value (individual optimal solution) is: when the new solution generated by the particle is dominated by the old solution, the individual extreme value remains unchanged; when the new solution dominates the old solution, the new solution is used as the individual extreme value; and when the new solution and the old solution are not dominant to each other, a solution is randomly selected as the individual extreme value.

[0097] The update strategy of the group extremum (global optimal solution) is: after each iteration, as the particle position is updated, the calculated Pareto optimal solution set will also be updated, and a particle is randomly selected from the updated Pareto solution as the group extremum for the next iteration.

[0098] S280, using individual extreme values ​​and group extreme values ​​to update the speed and position of each particle, as well as the new number of iterations.

[0099] In the embodiment of the present invention, the pre-configured particle speed and position update formula may be called to update the speed and position of each particle, and update the number of iterations.

[0100] Further, based on the above-mentioned embodiments of the invention, the particle velocity and position update formula can be expressed as follows:

[0101]

[0102] In the formula, v ij (t) is the j-th velocity component of the ith particle in the t-th iteration; x ij (t) is the j-th position component of the ith particle in the t-th iteration; ω inertiais the inertia coefficient, which is used to control the influence of the particle's previous velocity on the current velocity, which will affect the particle's global and local search capabilities; c 1 is the individual learning coefficient; c 2 is the global learning coefficient; r 1 and r 2 are two independent random numbers in the interval [0,1]; p ij (t) is the individual extreme value of the ith particle; p gj (t) is the group extreme value of the particle swarm.

[0103] S290: Determine whether the updated number of iterations satisfies the iteration termination condition.

[0104] In the embodiment of the present invention, it can be determined whether the number of iterations of the current iteration meets the pre-configured iteration termination condition. If so, S2100 is executed; if not, S2110 is executed.

[0105] S2100, if yes, then output the Pareto optimal solution set corresponding to the current number of iterations, and determine the target harmonic absorption current instruction in the Pareto optimal solution set according to the preset weight coefficients corresponding to the active device limit utilization objective function and the harmonic weight objective function.

[0106] In an embodiment of the present invention, if the iteration termination condition is met, the Pareto optimal solution set corresponding to the current number of iterations is directly output, and based on the preset weight coefficients corresponding to the active device limit utilization objective function and the harmonic weight objective function, the best global optimal solution is selected from the above Pareto optimal solution set, that is, the final target harmonic absorption current instruction.

[0107] Further, in S2100, according to the preset weight coefficients corresponding to the active device limit utilization objective function and the harmonic weight objective function, the target harmonic absorption current instruction is determined in the Pareto optimal solution set, which specifically includes the following steps:

[0108] A. Determine the first fitness value of the objective function of limiting the use of active devices corresponding to each Pareto optimal solution in the Pareto optimal solution set, and the second fitness value of the objective function corresponding to the harmonic weight;

[0109] B. For each Pareto optimal solution, determine the first product between the first fitness value and the corresponding first preset weight coefficient, and the second product between the second fitness value and the corresponding second preset weight coefficient, and use the sum of the first product and the second product as the objective function weight value;

[0110] C. Traverse the objective function weight values ​​corresponding to each Pareto optimal solution, and take the corresponding Pareto optimal solution with the largest objective function weight value as the target harmonic absorption current instruction.

[0111] S2110, if not, return to the step of determining the fitness value corresponding to each particle based on the active device maximum utilization objective function, the harmonic weight objective function and the fundamental current real-time value.

[0112] In the embodiment of the present invention, if the iteration termination condition is not met, the process returns to the step in S260 to execute the next round of iteration process of the optimization algorithm.

[0113] S2120. Perform harmonic absorption multiplexing control on the grid-connected converter based on the target harmonic absorption current instruction.

[0114] Figure 4 This is a flow chart of another method for multiple harmonic absorption and multiplexing of a grid-type converter and its active device limiting use provided by the second embodiment of the present invention. Figure 4 As shown, the method mainly includes the following steps:

[0115] 1. Establish a multi-harmonic absorption multiplexing control architecture for grid-type converters;

[0116] 2. Establish an active device loss model under the condition that the grid-connected converter output contains multiple harmonic combinations, where the real-time value of the fundamental current and the absorption current of each harmonic are inputs, and the active device loss power value is output;

[0117] 3. The real-time value of the fundamental current is calculated based on the active power and reactive power obtained by real-time measurement, and then input into the particle swarm computing module to iteratively solve the harmonic absorption current instruction;

[0118] 4. Each iteration of the particle swarm computing module calculates the loss of active devices of the grid-type converter through the active device loss model based on the multiple harmonic current combination input of the current iteration;

[0119] 5. Obtain a combination of multiple harmonic current absorption command values ​​(i.e., target harmonic absorption current command) that reaches the upper limit of active device loss of the grid-forming converter and meets the dual optimization goals of weight proportion distribution of each harmonic through particle swarm iterative calculation;

[0120] 6. Perform harmonic absorption multiplexing control on the converter based on the determined target harmonic absorption current command.

[0121] It should be noted that, in the embodiment of the present invention, under the condition of a larger grid harmonic current distribution, the use of the dynamic surplus capacity of the grid-forming converter to multiplex and absorb grid harmonics is set based on the condition of making up for it as much as possible.

[0122] The technical solution of the embodiment of the present invention determines the corresponding IGBT loss limit utilization objective function, diode loss limit utilization objective function and harmonic weight objective function according to the IGBT loss model and diode loss model constructed under the multi-harmonic absorption multiplexing control architecture of the grid-type converter, and then uses the fundamental current real-time value determined under the current working condition as the input of the particle swarm optimization algorithm, iteratively solves the active device limit utilization objective function and the harmonic weight objective function to obtain the optimal target harmonic absorption current instruction, and then performs harmonic absorption multiplexing control on the grid-type converter based on the target harmonic absorption current instruction, solves the problem that the remaining capacity of the converter cannot be effectively reused for harmonic absorption in the grid-type control architecture, and the active devices cannot be fully utilized, makes full use of the time-varying active working condition of the grid-type converter, reuses its extra capacity to absorb grid harmonics, so as to achieve the maximum utilization of its active devices, improves the utilization rate of the grid-type converter, and reduces the grid harmonic level, thereby improving the power quality of the grid.

[0123] The IGBT loss P is given below IGBT and diode loss P Diode The specific derivation process.

[0124] The instantaneous conduction loss of IGBT is:

[0125]

[0126] In the formula, v CE is the collector-emitter voltage; r CE is the on-resistance of the IGBT in the amplified state; V CE0 is the on-state voltage drop; i ac is the AC harmonic combination; k is the harmonic order; I k is the kth harmonic absorption current amplitude; f 1 is the fundamental frequency; is the kth harmonic absorption current phase angle.

[0127] According to the instantaneous loss calculation, we can get:

[0128]

[0129] Where τ(t) is the duty cycle that changes with time.

[0130] Since most of the harmonics in the power grid are 6k±1 order harmonics, when the low-order harmonic current on the AC side of the converter is mixed with the fundamental current for output, the current flowing through the active device is:

[0131]

[0132] Based on the current flowing through the active device, the average conduction loss of the IGBT can be obtained as follows:

[0133]

[0134] Where f(i,j) is a function of the harmonic order and can be expressed as:

[0135]

[0136] The switching loss of IGBT can be expressed as a quadratic function as follows:

[0137]

[0138] Where V DC is the DC voltage; V nom is the DC voltage reference value; coefficients a, b and c can be obtained by curve fitting.

[0139] For millisecond-level pulses, the output current i can be regarded as a constant, and the IGBT instantaneous switching loss can be expressed as:

[0140]

[0141] Furthermore, the average switching loss of IGBT is:

[0142]

[0143] In summary, the total loss P of IGBT is IGBT It can be expressed as:

[0144]

[0145] Similarly, the total loss P of the diode can be derived Diode for:

[0146]

[0147] In order to enable those skilled in the art to better understand the embodiments of the present invention, the following specific examples are used to illustrate the multi-harmonic absorption multiplexing of the grid-type converter and the method for limiting the use of active devices in the embodiments of the present invention. Taking a three-phase line voltage 380V grid-type converter as an example, its real-time active power P is measured. out The real-time reactive power Q is 6.37kW. out is 2.4kVar.

[0148]

[0149] The power factor of the grid is calculated to be 0.938, and the real-time value of the fundamental current is 18A.

[0150] By consulting the IGBT data sheet, we can obtain the loss rating P at room temperature 25°C. tot =250W, the switching loss varies with current as follows:

[0151] E sw =4.88*10 -4 i 2 +0.021i+0.07

[0152] After iterative calculation of particle swarm optimization, the amplitude and phase of each harmonic absorption current can be obtained, and the corresponding fitness evolution curve is as follows: Figure 5 shown.

[0153] According to the iterative optimization results, when the amplitude and phase of each harmonic absorption current meet the following table, the active device can be used to the maximum extent.

[0154] Absorbed current harmonic order Amplitude Phase 5 35.7301 -2.7550 7 13.6529 -0.2974 11 10.9366 1.4766 13 10.6495 2.0917 17 11.4468 -1.3798

[0155] Embodiment 3

[0156] Figure 6 This is a schematic diagram of the structure of a multi-harmonic absorption multiplexing device for a grid-type converter and a device for limiting the use of its active components provided in the third embodiment of the present invention. Figure 6 As shown, the device comprises:

[0157] The objective function determination module 31 is used to determine the corresponding objective function according to the active device loss model under the pre-established grid-type converter multi-harmonic absorption multiplexing control architecture; wherein the objective function at least includes: the active device limit utilization objective function and the harmonic weight objective function; the grid-type converter multi-harmonic absorption multiplexing control architecture includes: the basic grid-type control architecture, the current harmonic component calculation module and the harmonic compensation calculation module;

[0158] The instruction solving module 32 is used to iteratively solve the active device limit utilization objective function and the harmonic weight objective function based on the real-time measured active power and reactive power using a preset multi-objective optimization algorithm to obtain a target harmonic absorption current instruction;

[0159] The harmonic absorption multiplexing control module 33 is used to perform harmonic absorption multiplexing control on the grid-connected converter based on the target harmonic absorption current instruction.

[0160] The technical solution of the embodiment of the present invention determines the corresponding active device maximum utilization objective function and harmonic weight objective function according to the active device loss model constructed under the multi-harmonic absorption multiplexing control architecture of the grid-type converter, and then uses the active power and reactive power obtained by real-time measurement under the current working conditions as the input of the preset multi-objective optimization algorithm, and iteratively solves the active device maximum utilization objective function and the harmonic weight objective function to obtain the optimal target harmonic absorption current instruction, and then performs harmonic absorption multiplexing control on the grid-type converter based on the target harmonic absorption current instruction, which solves the problem that the remaining capacity of the converter cannot be effectively reused for harmonic absorption in the grid-type control architecture, and the active devices cannot be fully utilized, and makes full use of the time-varying active working conditions of the grid-type converter, reuses its extra capacity to absorb grid harmonics, so as to achieve the maximum utilization of its active devices, improves the utilization rate of the grid-type converter, and reduces the grid harmonic level, thereby improving the power quality of the grid.

[0161] Further, based on the above-mentioned embodiment of the invention, the objective function determination module 31 includes:

[0162] An active device loss model and harmonic weight objective function acquisition unit is used to acquire an active device loss model under a pre-established multi-harmonic absorption multiplexing control architecture of a grid-type converter, and to acquire a pre-configured harmonic weight objective function; wherein the active device loss model includes at least: an IGBT loss model and a diode loss model;

[0163] The active device limit usage objective function determination unit is used to determine the corresponding IGBT loss limit usage objective function and diode loss limit usage objective function as the active device limit usage objective function based on the IGBT loss model, the diode loss model and the corresponding rated losses.

[0164] Further, based on the above-mentioned embodiment of the invention, the preset multi-objective optimization algorithm at least includes: a particle swarm optimization algorithm; accordingly, the instruction solving module 32 includes:

[0165] A fundamental current real-time value determination unit is used to obtain the real-time measured active power and reactive power under the multi-harmonic absorption multiplexing control architecture of the grid-type converter, and determine the corresponding fundamental current real-time value by calling a preset fundamental current calculation formula according to the active power and reactive power;

[0166] A condition acquisition unit, used to obtain the optimization constraint conditions and iteration termination conditions corresponding to the particle swarm optimization algorithm;

[0167] An initialization unit, used to use the harmonic absorption current instruction to be solved as a particle in the particle swarm, and initialize the position and speed corresponding to each particle based on the optimization constraint condition;

[0168] A fitness value determination unit, used to determine the fitness value corresponding to each particle based on the active device limit utilization objective function, the harmonic weight objective function and the fundamental current real-time value;

[0169] An extreme value updating unit, used for updating the individual extreme value of the corresponding particle and the group extreme value of the particle group by using the fitness value;

[0170] An updating unit, used to update the velocity and position of each particle and the new iteration number using the individual extremum and the group extremum;

[0171] A judging unit, used to judge whether the updated number of iterations satisfies the iteration termination condition;

[0172] The first processing unit is used for outputting the Pareto optimal solution set corresponding to the current iteration number if yes, and determining the target harmonic absorption current instruction in the Pareto optimal solution set according to the preset weight coefficients corresponding to the active device limit utilization objective function and the harmonic weight objective function;

[0173] The second processing unit is used for returning to the step of determining the adaptation value corresponding to each particle based on the active device limited utilization objective function, the harmonic weight objective function and the fundamental current real-time value if no.

[0174] Further, based on the above-mentioned embodiment of the invention, the extreme value updating unit is specifically used for:

[0175] If the fitness value of a particle is greater than the fitness value corresponding to the individual extreme value of the particle, the individual extreme value of the particle is updated using the position of the particle in this iteration;

[0176] If the fitness value of a particle is less than the fitness value corresponding to the individual extreme value of the particle, the individual extreme value of the particle is kept unchanged in this iteration;

[0177] If the fitness value of a particle is greater than the fitness value corresponding to the group extreme value of the particle swarm, the group extreme value of the particle swarm is updated using the position of the particle in this iteration;

[0178] If the fitness value of a particle is less than the fitness value corresponding to the group extreme value of the particle swarm, the group extreme value of the particle swarm is kept unchanged in this iteration.

[0179] Further, based on the above-mentioned embodiments of the invention, according to the preset weight coefficients corresponding to the active device limit utilization objective function and the harmonic weight objective function, the target harmonic absorption current instruction is determined in the Pareto optimal solution set, including:

[0180] Determine a first fitness value of an active device limited utilization objective function corresponding to each Pareto optimal solution in the Pareto optimal solution set, and a second fitness value of a harmonic weight objective function corresponding to each Pareto optimal solution in the Pareto optimal solution set;

[0181] For each Pareto optimal solution, determine a first product between the first fitness value and the corresponding first preset weight coefficient, and a second product between the second fitness value and the corresponding second preset weight coefficient, and use the sum of the first product and the second product as the objective function weight value;

[0182] The objective function weight values ​​corresponding to each Pareto optimal solution are traversed, and the corresponding Pareto optimal solution with the largest objective function weight value is taken as the target harmonic absorption current instruction.

[0183] Further, based on the above-mentioned embodiments of the invention, the objective function of limiting the use of active devices is expressed as:

[0184]

[0185] Among them, δ 1 represents the IGBT wear-out limit usage objective function; P IGBT Indicates IGBT loss; P IGBTN Indicates the rated loss of IGBT; δ 2 represents the diode wear-out limit usage objective function; P Diode Represents diode loss; P DiodeN Indicates the rated loss of the diode;

[0186] The harmonic weight objective function is expressed as:

[0187]

[0188] Where Q represents the harmonic weight objective function; k represents the harmonic order; h k Indicates the kth harmonic importance weight coefficient; I k Indicates the kth harmonic absorption current amplitude.

[0189] Further, based on the above-mentioned embodiments of the invention, the IGBT loss model is constructed based on the conduction loss and switching loss of the converter IGBT; the diode loss model is constructed based on the conduction loss and switching loss of the converter diode.

[0190] The multi-harmonic absorption multiplexing device of the meshed converter and the limited use of its active devices provided in the embodiment of the present invention can execute the multi-harmonic absorption multiplexing device of the meshed converter and the limited use of its active devices provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0191] Embodiment 4

[0192] Figure 7 A schematic diagram of the structure of an electronic device 40 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0193] like Figure 7 As shown, the electronic device 40 includes at least one processor 41, and a memory connected to the at least one processor 41, such as a read-only memory (ROM) 42, a random access memory (RAM) 43, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 41 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 42 or the computer program loaded from the storage unit 48 to the random access memory (RAM) 43. In the RAM 43, various programs and data required for the operation of the electronic device 40 can also be stored. The processor 41, the ROM 42, and the RAM 43 are connected to each other through a bus 44. An input / output (I / O) interface 45 is also connected to the bus 44.

[0194] A number of components in the electronic device 40 are connected to the I / O interface 45, including: an input unit 46, such as a keyboard, a mouse, etc.; an output unit 47, such as various types of displays, speakers, etc.; a storage unit 48, such as a disk, an optical disk, etc.; and a communication unit 49, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 49 allows the electronic device 40 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0195] The processor 41 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 41 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The processor 41 executes the various methods and processes described above, such as the multi-harmonic absorption multiplexing of the grid-type converter and the method for limiting the use of its active devices.

[0196] In some embodiments, the multi-harmonic absorption multiplexing of the grid-type converter and the method for limiting the use of its active devices can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 48. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 40 via the ROM 42 and / or the communication unit 49. When the computer program is loaded into the RAM 43 and executed by the processor 41, one or more steps of the multi-harmonic absorption multiplexing of the grid-type converter and the method for limiting the use of its active devices described above can be executed. Alternatively, in other embodiments, the processor 41 can be configured to execute the multi-harmonic absorption multiplexing of the grid-type converter and the method for limiting the use of its active devices by any other appropriate means (for example, by means of firmware).

[0197] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0198] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0199] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0200] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0201] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0202] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0203] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0204] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for multiplexing multi-harmonic absorption of a grid-type converter and limiting the use of its active components, characterized in that: The method comprises: According to the pre-established active device loss model under the multi-harmonic absorption multiplexing control architecture of the grid-type converter, the corresponding objective function is determined; wherein the objective function at least includes: an active device limit utilization objective function and a harmonic weight objective function; the multi-harmonic absorption multiplexing control architecture of the grid-type converter includes: a basic grid-type control architecture, a current harmonic component calculation module and a harmonic compensation calculation module; Based on the real-time measured active power and reactive power, a preset multi-objective optimization algorithm is used to iteratively solve the active device limit utilization objective function and the harmonic weight objective function to obtain a target harmonic absorption current instruction; Harmonic absorption multiplexing control is performed on the grid-connected converter based on the target harmonic absorption current instruction.

2. The method according to claim 1, characterized in that The method of determining the corresponding objective function according to the pre-established active device loss model under the multi-harmonic absorption multiplexing control architecture of the grid-type converter includes: Obtaining the pre-established active device loss model under the multi-harmonic absorption multiplexing control architecture of the grid-type converter, and obtaining the pre-configured harmonic weight objective function; wherein the active device loss model at least includes: an IGBT loss model and a diode loss model; Based on the IGBT loss model, the diode loss model and the respectively corresponding rated losses, a corresponding IGBT loss limit utilization objective function and a diode loss limit utilization objective function are determined as the active device loss limit utilization objective function.

3. The method according to claim 1, characterized in that The preset multi-objective optimization algorithm at least includes: a particle swarm optimization algorithm; The active power and reactive power obtained by real-time measurement are iteratively solved by using a preset multi-objective optimization algorithm to the active device limit utilization objective function and the harmonic weight objective function to obtain a target harmonic absorption current instruction, including: The active power and the reactive power measured in real time under the multi-harmonic absorption multiplexing control architecture of the grid-type converter are obtained, and a preset fundamental current calculation formula is called according to the active power and the reactive power to determine the corresponding fundamental current real-time value; Obtaining optimization constraints and iteration termination conditions corresponding to the particle swarm optimization algorithm; The harmonic absorption current instruction to be solved is used as a particle in a particle swarm, and the position and speed corresponding to each particle are initialized based on the optimization constraint condition; Determine the adaptation value corresponding to each of the particles based on the active device limit utilization objective function, the harmonic weight objective function and the fundamental current real-time value; Using the fitness value to update the individual extreme value of the corresponding particle and the group extreme value of the particle group; Using the individual extreme value and the group extreme value, the speed and position of each particle and the new number of iterations are updated; Determine whether the updated number of iterations meets the iteration termination condition; If yes, output the Pareto optimal solution set corresponding to the current number of iterations, and determine the target harmonic absorption current instruction in the Pareto optimal solution set according to the preset weight coefficients corresponding to the active device limit utilization objective function and the harmonic weight objective function; If not, return to the step of determining the adaptation value corresponding to each particle based on the active device maximum utilization objective function, the harmonic weight objective function and the fundamental current real-time value.

4. The method according to claim 3, characterized in that The updating of the individual extreme value of the corresponding particle and the group extreme value of the particle group by using the fitness value includes: If the fitness value of the particle is greater than the fitness value corresponding to the individual extreme value of the particle, the individual extreme value of the particle is updated using the position of the particle in this iteration; If the fitness value of the particle is less than the fitness value corresponding to the individual extreme value of the particle, the individual extreme value of the particle is kept unchanged in this iteration; If the fitness value of the particle is greater than the fitness value corresponding to the group extreme value of the particle group, the group extreme value of the particle group is updated using the position of the particle in this iteration; If the fitness value of the particle is less than the fitness value corresponding to the group extreme value of the particle group, the group extreme value of the particle group is kept unchanged in this iteration.

5. The method according to claim 3, characterized in that: The determining the target harmonic absorption current instruction in the Pareto optimal solution set according to the preset weight coefficient corresponding to the active device limited use objective function and the harmonic weight objective function includes: Determine a first fitness value of the active device limited utilization objective function corresponding to each Pareto optimal solution in the Pareto optimal solution set, and a second fitness value corresponding to the harmonic weight objective function; For each of the Pareto optimal solutions, respectively determine a first product between the first fitness value and a corresponding first preset weight coefficient, and a second product between the second fitness value and a corresponding second preset weight coefficient, and use the sum of the first product and the second product as the objective function weight value; The objective function weight values ​​corresponding to each of the Pareto optimal solutions are traversed, and the corresponding Pareto optimal solution with the largest objective function weight value is taken as the target harmonic absorption current instruction.

6. The method according to claim 2, characterized in that The active device limit utilization objective function is expressed as: Wherein, δ1 represents the IGBT loss limit utilization objective function; P IGBT Indicates IGBT loss; P IGBTN represents the rated loss of IGBT; δ2 represents the objective function of the diode loss limit; P Diode Represents diode loss; P DiodeN Indicates the rated loss of the diode; The harmonic weight objective function is expressed as: Wherein, Q represents the harmonic weight objective function; k represents the harmonic order; h k Indicates the kth harmonic importance weight coefficient; I k Indicates the kth harmonic absorption current amplitude.

7. The method according to claim 2, characterized in that The IGBT loss model is constructed based on the conduction loss and switching loss of the converter IGBT; the diode loss model is constructed based on the conduction loss and switching loss of the converter diode.

8. A multi-harmonic absorption multiplexing device for a grid-type converter and a device for limiting the use of active components, characterized in that: The device comprises: The objective function determination module is used to determine the corresponding objective function according to the pre-established active device loss model under the multi-harmonic absorption multiplexing control architecture of the grid-type converter; wherein the objective function at least includes: the active device limit utilization objective function and the harmonic weight objective function; the multi-harmonic absorption multiplexing control architecture of the grid-type converter includes: a basic grid-type control architecture, a current harmonic component calculation module, and a harmonic compensation calculation module; An instruction solving module is used to iteratively solve the active device limit utilization objective function and the harmonic weight objective function based on the real-time measured active power and reactive power using a preset multi-objective optimization algorithm to obtain a target harmonic absorption current instruction; The harmonic absorption multiplexing control module is used to perform harmonic absorption multiplexing control on the grid-connected converter based on the target harmonic absorption current instruction.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for multi-harmonic absorption and multiplexing of a grid-type converter and the limited use of its active devices as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the multi-harmonic absorption and multiplexing of a grid-type converter and the method for limiting the use of its active components as described in any one of claims 1 to 7 when executed.

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